Manufacture of sulphonated products



Patented Dee.

Ralph 1!. Beach, Newark. N. 3., assignor to National Oil Products Co Harrison,

N. 1., a corporation of New Jersey Drawing. Application May 21, 1939,

Serial No. 210.119

8 Claims. (01. 260-400) This invention relates to the manufacture of sulphonated fatty acid compounds, more particularly to the manufacture of light-colored or colorless sulphonated fatty acid compounds.

agents, foaming agents, rust inhibitors, flotation promoters and for a large number of other purposes well known to those skilled in the art. However, these sulphonated products in many cases possess undesirable dark colors, due in part to the discoloration which maybe induced by contacting the oil, fat, wax or fatty acid with sulphuric acid, and in part to the impurities which may be present in the substance reacted with the sulphuric acid. The dark color not only detracts from the appearance of the product, but in some cases renders it unsuitable for use; for example, if it is desired to employ such a sulphonated product to treat textiles, leather or other fibrous material, it is particularly important that the product contains no coloring matter which will in any way discolor the fibrous material. While it is possible to prepare sulphonated products of suitable color and odor from refined oils, fats, waxes or fatty acids, these refined substances are comparatively expensive and therefore unrefined substances are usually employed.

According to U. S. Patent 1,734,050, light-colored sulphonated oils, fats, waxes and fatty acids may be obtained by sulphonating an oil, fat, wax or fatty acid in the presence of a bleaching agent, such as a peroxide, perborate, percarbonate, sulphite, hydrosulphite and the like; the patent states the bleaching effect may be assisted by subjecting the oil, fat, wax or fatty acid to a preliminary bleach, and also by bleaching the finished product. However, the process of this patent has not been employed successfully for two reasons. In the first place, excessively large quantities of bleaching agent are required as is evidenced by the fact that in each of the examples from 14 to 16 kg. of bleaching agent per 100 kg. of oil are employed. The use of such large amounts of bleaching agent not only renders the process of this patent highly ineconomical, but also the presence of such large quantities of bleaching agent in the sulphonation reaction mixture tends to interfere with the course kg. of a 30% aqueous solution of hydrogen peroxide when sulphonating 100 kg. of castor oil introduces such an amount of water into the sulphonation mixture that a product having a low 80: content is obtained and hydrolysis of the sulphonated product occurs. In the second place, many of the bleaching agents mentioned in this patent do not produce satisfactory products when used as therein indicated. For example, hydrogen peroxide only effects a temporary bleach of sulphonated oils and the like, the color returning after the sulphonated product is permitted to stand for a period of time; alkali hydrosulphites impart a vile odor to the sulphonated product, and in many cases actually darken the product rather than bleaching it; perborates and hypochlorites also give the sulphonated product a disagreeable odor. Furthermore, if sulphonated products are treated after neutralization with sulphites or bisulphites, in accordance with the teachings of this patent, products having distinct haziness are produced.

It will be evident from the above discussion that U. S. Patent 1,734,050 does not teach the art a process for economically producing permanently light-colored and substantially odorless sulphonated oils, fats, waxes and fatty acids, but rather leaves the art in a complete state of confusion with respect to the manner by which such products may readily be obtained. After extensive experimentation in this field, I have now found that colorless or light-colored sulphonated products which retain their desirable color even after prolonged standing and are free of undesirable odors may be obtained in a simple and effective manner in accordance with the inventlon hereinafter described.

It is an object of this-invention to produce light-colored or colorless sulphonated fatty acid compounds which retain their desirable color and possess substantially no undesirable odor from unrefined fatty acid compounds.

It is a further object of this invention to effect the production of these products in a simple and economical manner.

I have now made the surprising discovery that substantially colorless or light-colored suiphonated fatty acid compounds which retain their desirable color and have substantially no undesirable odor may be produced from unrefined fatty acid compounds by incorporating a relatively small amount of a compound capable of evolving sulphur dioxide upon contact with acid in the aqueous solution employed to wash of the sulphonation; for example, the use of 16 the sulphonation reaction mixture in accordance fatty acid compound treated.

with the well known method of sulphonation. I prefer to add to the aqueous wash solution a relatively small amount of a water-soluble salt of sulphurous acid, since I have found these salts effect an excellent bleaching of the sulphonated product. According 'to my novel process, an amount of a compound capable of evolving sulphur dioxide upon contact with acid equivalent to betweemabout 0.05% and about 4% of the fatty acid compound treated is sufficient to effect the production of the desired sulphonated products; this amount,it will be noted, is far less than that required in accordance with the process heretofore described. The products obtained in accordance with my invention remain colorless or light-colored even after prolonged standing and possess no undesirable odor. For purposes of convenience, the term fatty'acid compound" used throughout the specification and claims is intended'to include oils, fats, waxes, fatty acids and derivatives of fatty acids such as esters thereof other than glycerides which may be sulphonated. It is tobe understood that the term sulphonated fatty acid. compounds is intended to include not only fatty acid compounds which have been sulphonated in the strict sense of the term, but also compounds which have been sulphated; this use of the term sulphonated corresponds to the manner in which it is generally employed in the art. The process of my invention is applicable wherever an organic compound is sulphonated and the sulphonated product then washed while still in an acid condition, as distinguished from those processe! which involve neutralization of the sulphonated product directly after the sulphonation step.

As is well known in the art, the general method of sulphonating fatty acid compounds, such as castor oil, teaseed oil, oleic acid, recinoleic acid, sperm oil, etc., involves reacting the fatty acid compound with a suitable sulphonating agent, washing the reaction mixture with an aqueous solution to remove the excess sulphonating agent, neutralizing the washed product and finishing the neutralized product as desired. The sulphonation step is ordinarily carried out by mixing between about and about 100 parts of concentrated sulphuric acid or oleum with approximately 100 parts of the fatty acid compound to be treated, and then reacting this mixture at temperatures between about 10 and about C. for between about 1 and about 6 hours. In accordance with my invention, the reaction mixture thus obtained is then washed with an aqueous solution containing an amount of a compound capable of evolving sulphur dioxide upon contact with the acid sulphonation mass equivalent to between ah "t 0.05% and about 4%, preferably between aoout 3% and about 3/ of the The preferred compounds used in accordance with my invention are the water-soluble salts of sulphurous acid, such as the sodium, potassium and ammonium sulphites, bisulphites and pyrosulphites, since these salts have an excellent bleaching action when used in accordance with my invention, and, furthermore, do not contaminate the sulphonated products as they may be readily washed therefrom; this last factor is of particular importance since the presence of salts in the sulphonated product tends to produce an undesirable haziness. It is to be understood, however, that other compounds capable of evolving sulphur dioxide upon contact with acid may be employed. Preferably, the reaction mixture is tion to partially neutralize the excess acid. The

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amount of wash solution employed may vary widely, but generally an amount equivalent to about four times the amount of oil sulphonated is satisfactory. The temperature of the washing may vary to some extent, but generally between about 40 C. and about 50 C. is most suitable. The time of contact of the wash solution with the reaction mass may vary widely, but between about and about 1 hour is ordinarily sufficient. The washing may be carried out by agitating the sulphonated mass with the washing solution or by contacting the washing solution with the mass countercurrently or in any other manner well known to the art.

After the sulphonated mass has been washed in accordance with my invention, the aqueous washing medium may be withdrawn by permitting the mass to settle and the sulphonated material may then be neutralized in any suitable manner, such as, for example, by reaction with an aqueous solution of sodium carbonate. The mass may then be permitted to settle and the sulphonated product withdrawn. I have found that in every case the process of my invention produces brilliantly clear, light-colored or colorless sulphonated fatty acid compounds which retain their desirable color even after prolonged standing and possess substantially no undesirable odor.

The following examples are illustrative of my invention. Amounts are given in parts by weight.

Example I 300 parts of castor oil and parts of 98% sulphuric acid were reacted at a temperature of 25 C. for 4 hours. The product of this reaction was then washed with a solution comprising parts of sodium chloride and 10 parts of sodium bisulphite dissolved in 1200 parts of water at a temperature of 45 C. for 40 minutes. At the end of this time the salt water was withdrawn and the mixture neutralized with a soda solution to a pH value of about 4.5. It was then permitted to settle to remove the salt water, and the neutralized product withdrawn. A brilliantly clear sulphonated castor oil product was obtained having a very light color and possessing substantially no undesirable odor. The product was tested in a Lovibond Tintometer and was found to have a reading of 20 llow and 3.8 red; sulphonated castor oil produced in the same manner, except that no sodium bisulphite was introduced into the wash water, had a Lovibond reading of 25 yellow and 4.9 red. Furthermore, the product did not darken even after long standing.

Example II 300 parts of crude oleic acid and 180 parts of 98% sulphuric acid were reacted at a temperature of 20 C. for 1 hour. The reaction product was then washed with a solution comprising 80 parts of sodium chloride and 10 parts of sodium pyrosulphite dissolved in 1000 parts of water at a temperature between 40 C. and 50 C. for 1 hour. At the end of this time the salt water was withdrawn and the mixture neutralized with a soda solution until slightly alkaline to methyl orange. The neutralized mass was then permitted to settle to remove the salt water and the product withdrawn. The sulphonated product possessed a very light color and substantially no undesirable odor; furthermore, it did not darken even after long standing.

Example III 300 parts of olive oil and 90 parts of 98% sulphuric acid were reacted at a temperature of 20 C. for about 1 hour. The reaction product was then washed with a solution compr ing 80 parts of sodium chloride and parts 0; dium pyrosulphite dissolved in 1000 parts of water at a temperature between 40 C. and 50 for 1 hour. At the end of this time the salt water was withdrawn and the mixture neutralized with a soda solution until slightly alkaline to methyl orange. The neutralized mass was then permitted to settle to remove the salt water and the product withdrawn. The sulphonated product possessed a very light color and substantially no undesirable odor; furthermore, it did not darken even after long standing.

Example IV 300 parts of sperm oil and 90 parts of 98% sulphuric acid were reacted at a temperature of C. for about 1 hour. The reaction product was then washed with a solution comprising 80 parts of sodium chloride and 10 parts of sodium pyrosulphite dissolved in 1000 parts of water at a temperature of between 40 C. and 50 C. for 1 hour. At the end of this time the salt water was withdrawn and the mixture neutralized with a soda solution until slightly alkaline to methyl orange. The neutralized mass was then permitted to settle to remove the salt water and the product withdrawn. The sulphonated product possessed a very light color and substantially no undesirable odor; furthermore, it did not darken even after long standing.

It will be evident from the above description that my invention provides a process for obtaining light-colored or colorless and substantially odorless sulphonated fatty acid compounds in a simple and highly economical manner as contrasted with that of the prior art. The products of my invention are particularly suitable for treating textiles, leather, and other fibrous materials, and may also be used as detergents, plasticizers, defoamers, wetting, dispersing and emulsifying agents, foaming agents, rust inhibitors, flotation promoters and for a large number of other purposes known to those skilled in the art. My invention provides a solution for a problem which has long been before the art, and hence will be of great value to those engaged in the preparation of sulphonated fatty acid compounds.

Since certain changes may be made in carrying out the above process without departing from the scope of the invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In the manufacture of light-colored or colorless sulphonated fatty acid compounds involving sulphonating a fatty acid compound and washing the acid reaction mass, the improvement which comprises incorporating in the washing medium a relatively small amount of a compound capable of evolving sulphur dioxide upon contact with acid.

2. In the manufacture of light-colored or colorless sulphonated fatty acid compounds involving sulphonating a fatty acid compound and washing the acid reaction mass, the improvement which comprises incorporating in the washing medium a relatively small amount of a salt of sulphurous acid.

3. In the manufacture of sulphonated fatty acid compounds involving sulphonating a fatty acid compound and washing the acid reaction mass, the improvement which comprises incorporating in the washing medium a relatively small amount of a salt of sulphurous acid selected from the group consisting of alkali and ammonium sulphites, bisulphites and pyrosulphites.

4. In the manufacture of sulphonated-fatty acid compounds involving sulphonating a fatty acid compound and washing the acid reaction mass, the improvement which comprises incorporating in the washing medium an amount of a compound capable of evolving sulphur dioxide upon contact with acid equivalent to between about 0.05% and about 4% of the fatty acid compound treated.

5. In the manufacture of sulphonated fatty acid compounds involving treating a fatty acid compound with sulphuric acid, washing the acid reaction mass with an aqueous sodium chloride solution and neutralizing the washed mas, the improvement which comprises incorporating in the sodium chloride solution an amount of a salt of sulphurous acid selected from the group consisting of alkali and ammonium sulphites, bisulphites, and pyrosulphites equivalent to between about 3% and about 3.5% of the fatty acid compound treated.

6. In the manufacture of sulphonated castor oil involving treating castor oil with sulphuric acid, washing the acid reaction mass with an aqueous sodium chloride solution and neutralizing the washed mass, the improvement which comprises. incorporating in the sodium chloride solution a relatively small amount of a salt of sulphurous acid selected from the group consisting of alkali and ammonium sulphites, bisulphites and py osulphites.

7. In the manufacture of sulphonated oleic acid involving treating oleic acid with sulphuric acid, washing the acid reaction mass with an aqueous sodium chloride solution and neutralizing the washed mass, the improvement which comprises incorporating in the sodium chloride solution a relatively small amount of a salt of sulphurous acid selected from the group consisting of alkali and ammonium sulphites, bisulphites and pyrosulphites.

8. In the manufacture of sulphonated sperm oil involving treating sperm oil with sulphuric acid, washing the acid reaction mass with an aqueous sodium chloride solution and neutralizing the washed mass, the improvement which comprises incorporating in the sodium chloride solution a relatively small amount of a salt of sulphurous acid selected from the group consisting of alkali and ammonium sulphites, bisulphites and pyrosulphites.

, RALPH M. BEACH. 

